ideology

An ideology is a set of opinions or beliefs of a group or an individual. Very often ideology refers to a set of political beliefs or a set of ideas that characterize a particular culture.

Capitalism, communism, socialism, and Marxism are ideologies. But not all -ism words are. Think: cronyism (a system of graft whereby friends unfairly help each other make money.) Our English noun is from French idéologie. The suffix –logy, used with many English words describing theories or doctrines, is from Greek logos "word, reason, speech, account."

the political and economic theories of Lenin which provided the guiding doctrine of the Soviet Union; the modification of Marxism by Lenin stressed that imperialism is the highest form of capitalism (which shifts the struggle from developed to underdeveloped countries)

the economic and political theories of Karl Marx and Friedrich Engels that hold that human actions and institutions are economically determined and that class struggle is needed to create historical change and that capitalism will ultimately be superseded by communism